Method of thiocarbamoylchitosan obtainment
SUBSTANCE: method of obtaining thiocarbamoylchitosan (TCC) involves chitosan reaction with ammonium rhodanide solution in organic thiocarbamide solvent at 110-150°C at weight ratio of chitosan to ammonium rhodanide of 100 : 90 - 440, with further water extraction of cooled reaction mass and product drying.
EFFECT: obtainment of TCC with addition degree of 0,31-1,12.
1 tbl, 7 ex
The invention relates to the synthesis of thiocarbamoyl derivatives of polysaccharides, namely the method of obtaining thiocarbamoylation (tariff and qualifying characteristics). These compounds are used as components of antibacterial agents and as sorbents of heavy metals.
Known only way to obtain tariff and qualifying characteristics by reacting chitosan with a 11% solution of ammonium thiocyanate in ethanol by heating the mixture under reflux (temperature ~80°C) and stirring for 12 hours at a ratio of 100 g of chitosan 91 g of ammonium thiocyanate. After sorption of silver ions the product is used as antibacterial agents (Carbohydr. Polym. 2005, 60, 33-38; CN1712417 A).
The disadvantage of this method of obtaining tariff and qualifying characteristics is the use of alcohol solutions when heated, which requires the inverse of the refrigerator, i.e., not only heating, but also cooling unit. Chitosan in alcohol insoluble, so the reaction proceeds in a heterogeneous system under stirring - this allows to obtain tariff and qualifying characteristics with a sulfur content not higher than 0,6% (corresponds to degree of annexation - 0,035).
Because sorption properties of tariff and qualifying characteristics in relation to ions of silver (or any other heavy metal ions), and thus a unique antimicrobial properties of silver derivatives, due to the number of entered thiocarbamoyl groups (residues tibmachuni the s), the most valuable should be considered as target product - tariff and qualifying characteristics with a greater degree of connection.
The problem solved by the invention is a simplified method of obtaining tariff and qualifying characteristics and improve its quality.
The problem is solved by the interaction of chitosan with a solution of ammonium thiocyanate in the thiourea (concentration of ammonium thiocyanate 32-68%) at a ratio of 100 g of chitosan from 90 to 440 g of ammonium thiocyanate at 110-150°C for 4-6 hours, extraction of the cooled reaction mixture with water and subsequent drying of the product.
Use as an organic solvent thiourea does not require the use of a reverse refrigerator. The formation of chitosan in the proposed conditions of homogeneous gel allows you to carry out the process without stirring at 110-150°C. the process Time is reduced by 2-3 times, the degree of annexation thiocarbamoyl groups increases 9-32 times (0,31-1,12) with the same or greater value of the yield of the target product, which allows more efficient use of the equipment and increases the value of tariff and qualifying characteristics for use as a sorbent.
At temperatures below 110°C, the inhomogeneous environment that slows down the process, above 150°C is markedly reduced yield due to processes of degradation of the polymer chain. Carrying out the reaction for smaller periods of time (less than 4 hours) inefficient because the degree is of prisoedinenia low (less than 0.3), large periods of time (over 6 hours) does not lead to a further increase in the degree of connection.
The process is carried out by heating in the reactor, the product is then extracted with water to conventional Soxhlet extractions, dried in a drying Cabinet with air. The composition of the obtained tariff and qualifying characteristics characterize the content of S and N % of the data of elemental analysis, the presence of introduced thiocarbamoyl groups - IR spectroscopy using consoles diffuse reflection.
The proposed solution is illustrated by the following examples.
A mixture of 3.3 g (0.02 mol) of chitosan, and 10.5 g (is 0.135 mol) of ammonium thiocyanate and 5 g (0,065 mol) of thiourea are heated up to 130°C, incubated 10 min before the formation of gel-like mass is then heated at the same temperature for 6 h and cooled. The resulting product is subjected to cold extraction water (to conventional Soxhlet extractions) to negative reactions to the thiocyanate ion (ferric salt). The product is dried at 50°C until constant weight, the yield of 3.8, According to the elemental analysis of sulfur content is 12,11%, which corresponds to the degree of annexation by 1.12. In the IR spectrum of the product has an absorption band 1620 cm-1characteristic relation S=C, and 1404 cm-1for S=C-N<.
The method further experiments corresponds to example 1. Reaction conditions and characteristics of the products obtained are presented in Alice 1.
Conditions for obtaining tariff and qualifying characteristics and features.
|No.||chitosan, g||NH4SCN, g (%)||CS(NH2)2g||mass. aspect]. NH4SCN: chitosan||temperature, °C||time, h||*g||S %||**degree accession|
|the placeholder||16,1||15,2 (11)||ethanol 120||90:100||~80||12||1||0,6||0,035|
|2||4,95||a 21.75 (68)||10,35||440:100||10||5||1,1||7,87||0,56|
*Output per 1 g of the loaded chitosan.|
** Degree of attach (DS) was calculated by the formula DS=1/(nN/nS-1), where nN/nS- the molar ratio between the elements determined from the data of elemental analysis.
The method of obtaining thiocarbamoylation interaction of chitosan with a solution of ammonium thiocyanate in an organic solvent by heating, characterized in that the organic solvent used thiourea, the reaction is carried out at a temperature of 110-150°C and the mass ratio of chitosan:ammonium thiocyanate 100:90-440 with subsequent extraction of the cooled reaction mixture with water and drying the product.
FIELD: chemistry; pharmacology.
SUBSTANCE: invention refers to new hyaluronic acid derivatives to be used in medicine and pharmacology. There are disclosed hyaluronic acid derivatives of general formula ,
where R=OH or R1 and ratio R1:OH varies 8:92 to 100:0 , , , ,
, , ,
, , ,
of lowered biodegradability as compared to natural hyaluronic acid.
EFFECT: production of new hyaluronic acid derivatives.
3 dwg, 1 tbl, 3 ex
FIELD: food products.
SUBSTANCE: method proposed envisages blend of two solutions and the resultant compound degasation and polymerisation. The first solution production process envisages addition of water and ethylenediamine - N,N,N',N' - tetraacetic acid to chitosan or derivatives thereof, mechanical agitation of the resultant compound, further load of acid for pH to be 4.0, heating to produce a solution, load of alkali for deposition of a sediment, the sediment collection and distilled water flushing for pH to be 6.2, further successive load of acid for the sediment complete dissolution, alkali for pH to be 6.2 and acide for pH to be 5.6, centrifugation, distilled water addition and vacuum degasation of the solution thus produced. The second splution is produced by way of having distilled water, acid and sodium or potassium persulphate to N,N,N',N' - tetramethylethylenediamine.
EFFECT: combination of hydrogel plasticity properties with prophylactic and protective properties of chitosan or derivatives thereof to have been preserved after polymerisation.
FIELD: chemistry, biochemistry.
SUBSTANCE: invention relates to biotechnology. The proposed method comprises thermal processing of larva, separated from a substratum upon termination of their cultivation, for 2 to 15 min at 75 to 100°C. Thermal processing over, larvae are crushed, chitine-containing fraction is separated from hemolymph. Now, the chitine-containing precipitate as-washed and crushed is subjected to enzymic hydrolysis at temperature 35 to 46°C with pH of 6.5 to 8.5 till achieving amine nitrogen content not below 0.8 G/%. Then, the separated chitine-containing precipitate is subjected to alkaline hydrolysis at continuous mixing for 60 to 90 min at 55 to 65°C. Finally, the aforesaid chitine-containing precipitate is subjected to demineralisation by 1.5 to 3.0 percent solution of hydrochloric or nitric acid for 30 to 40 min at 60 to 70°C. After that, the precipitate containing chitine is rinsed with water till pH of 6.5 to 7.5 and dried.
EFFECT: increase in biological value of target products with simultaneous increase in their number and simplification of process method.
4 cl, 1 ex
SUBSTANCE: invention describes a method of epi-K5-N-sulfate oversulfation for obtaining epi-K5-amine-O-oversulfate with very high sulfation degree, which produces new epi-K5-N,O-oversulfate derivatives with sulfation degree of 4-4.6 on following N-sulfation, the derivatives being almost inactive to fibrillation parametres and applicable in pharmaceutical compositions with antidermatitis and antiviral effect. The invention also describes new low-molecular epi-K5-N-sulfates applicable as transit products in obtaining the respective low-molecular epi-K5-N,O-oversulfate derivatives.
EFFECT: method of epi-K5-N-sulfate oversulfation for obtaining epi-K5-amine-O-oversulfate with extremely high sulfation degree.
55 cl, 4 dwg
FIELD: medicine; pharmacology.
SUBSTANCE: offered invention concerns medicine and pharmacology, exactly to method of Chitosan production. Method includes milling of natural chitin-containing raw material, alternating by turn three stages of raw material deproteinisation, and three stages of decalcification, deproteinisation stages are carried out by sodium hydroxide solution of concentration 3-5% produced by diaphragm electrolysis method within 3-4 hours at temperature 60-65°C; decalcification stages are performed by 3-5% hydrochloric acid solution at temperature 20-25°C within 1-3 hours; deacetylation is performed by 49-55% sodium hydroxide produced by diaphragm electrolysis method; deproteinisation and decalcification stages are performed in series connected six steel devices with internal glass-enamel coating, equipped with stirrers, thermopools, connections for reagents feeding and disposal, jackets for reactionary mass cooling and heating. Afterwards deacetylation follows with 49-55% sodium hydroxide produced by diaphragm electrolysis method. Process is conducted at temperature 95-105°C within 7-9 hours and followed by washing, spinning and drying of finished Chitosan.
EFFECT: production of high-clean Chitosan.
SUBSTANCE: invention refers to medicine and describes method of glycosaminoglycan release from mineralised connective tissue, containing enzymatic hydrolysis, deproteinisation, deposition, and characterised by the fact that demineralisation is performed within 20 h using 0.5 H HC1, enzymatic hydrolysis is performed within 18 h using pepsin enzyme, deproteinisation is performed by adding of ammonium sulphate to 75% saturation, glycosaminoglycans are deposited with 4% potassium acetate in 96% ethanol, re-deposited with ethanol and lyophilised. Glycosaminoglycans are exposed to chromatographic separation using "ДЕАЕ"-sephadex A-25, and lyophilised. This method is easy-to-use, realised in laboratory environment of patient care institutions, and time-saving.
EFFECT: easy and saving method of glycosaminoglycan release from mineralised connective tissue.
1 ex, 2 dwg
FIELD: fish processing industry.
SUBSTANCE: invention relates to method for production of chitin from raw materials belonging to class Crustacea. Claimed method includes maxillopod grinding, enzymatic hydrolysis of proteins, hydrolyzate separation followed by drying, demineralization deproteinization. Enzymatic hydrolysis is carried out by using own maxillopod enzymes. Autoenzymolisis is carried out in aqueous medium with addition of bioconserving agents in raw/bioconserving agent solution of 1:(3-4) for 21 h at 35°C. As bioconserving agent milky whey or aloe juice is used. After protein hydrolyzate separation chitin semi-product is demineralized.
EFFECT: decreased product cost, product of improved quality, environmentally friendly method.
3 cl, 7 ex, 2 tbl
FIELD: polymers, chemical and biochemical technology.
SUBSTANCE: method for preparing oligomers of chitosan is carried out by enzymatic hydrolysis of chitosan in an aqueous solution at pH 3.0-4.4. Hydrolysis is carried out in the presence of chitosanase and papain taken in the ratio = 1:(1-1.2) by mass. Hydrolyzate is treated with anion-exchange resin, filtered, concentrated to the content of water 62-80% and dried. Method provides decreasing losses by 50-70% and enhancing quality of the end product. Invention can be used in food industry and medicine.
EFFECT: improved preparing method.
2 cl, 4 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention describes chitosanium perchlorate of the following formula: C6O4H9NH3ClO4. This compound shows such properties as explosion-proof, absence of toxicity, resistance to moisture and heating, mechanical effects and possesses high oxidizing and binding properties. This allows its using in power-consuming compositions in mixture with chitosanium dodecahydro-clozododecaborate wherein it functions as a binding agent. The quantitative ratio between chitosanium dodecahydro-clozododecaborate in the composition is determined by required regimen of combustion: the more content of chitosanium perchlorate the higher activity of the composition.
EFFECT: improved preparing method, valuable properties of composition.
3 cl, 1 dwg, 4 ex
FIELD: derivatives of chitosan.
SUBSTANCE: invention relates to preparing biologically active chitosan substances and their derivatives. Invention describes a modified chitosan substance showing pH-neutral reaction and plastic structure of chitosan particles as fractal chitosan particles of size of nanofractals from 1 nm, not less, and to 5000 nm, not above, or as cross-linked net-shaped polymer having multiple cavities of size from 1 nm, not less, to 50 nm, not above. Invention describes methods for their preparing. Invention provides high transdermal penetration of chitosan substance and enhanced capacity for administration of medicinal or biologically active substances into chitosan substance. Invention can be used in manufacturing cosmetic, curative-cosmetic, pharmacological preparations, biologically active food supplements and foodstuffs.
EFFECT: improved and valuable properties of chitosan substances.
14 cl, 4 tbl, 7 dwg, 9 ex
FIELD: fish industry.
SUBSTANCE: method involves providing deacetylation of raw material with the use of preliminarily cooled alkaline solution; washing and drying. Deacetylation process is performed in three stages, first stage being performed for 7 days and subsequent two stages being performed for 2 hours each, combined with thermal processing at temperature of 55-590C. Washing process is provided after each deacetylation stage.
EFFECT: provision for producing of chitosan from chitin of cancerous with increased extent of deacetylation, while native properties of natural polymer being kept, without breaking of glycoside binding chain.
FIELD: organic chemistry.
SUBSTANCE: claimed method includes subsequent chitosane-containing raw material with non-polar liquefied gas, water, alkali, water, acid, water, alkali, and water to produce target product in form of solid residue, wherein in at least first extraction step pressure in reaction mixture is periodically released to provide extractant boiling, and than increased up to starting value.
EFFECT: method with reduced energy consumption.
FIELD: chemical technology of natural compounds.
SUBSTANCE: invention describes a method for preparing water-soluble derivatives of chitosan. Method involves treatment of chitosan with acid medium up to its swelling wherein vapor medium water-acid is used as acid medium. Treatment of chitosan is carried out with vapor of monobasic acid aqueous solution taken among the group including hydrochloric acid, formic acid and acetic acid. Method allows simplifying technology in preparing water-soluble derivatives of chitosan.
EFFECT: improved preparing method.
4 cl, 1 tbl, 9 ex
FIELD: chemistry and technology of derivatives of polysaccharides, chemical technology.
SUBSTANCE: invention relates to methods for preparing chitosan esters. Invention describes a method for preparing chitosan polyethylene glycol ester that involves dissolving chitosan in acetic acid followed by alkalization. Then the reaction mixture is subjected for effect of ethylene oxide under pressure 1-3 atm and temperature 60-100°C, and the concentration of reaction mass is corrected by addition of distilled water up to the density value of solution 1.030-1.032 g/cm3. Then the reaction mass is purified by electrodialysis at the rate value of solution in treatment chambers 3.0 cm/s, not less, temperature 20-45°C, the current density value 0.25-0.75 A/dm2 and the constant volume of the reaction mass. Method provides enhancing the effectiveness of purification by electrodialysis due to reducing energy consumptions. Chitosan esters can be used in medicine, cosmetics, food and chemical industry.
EFFECT: improved preparing method.
FIELD: organic chemistry of natural compounds, chemical technology, medicine.
SUBSTANCE: invention relates to the group of chitosan-containing compounds. Invention relates to synthesis of modified chitosan of the following structure: wherein n = 150-1400. The modified chitosan possesses the bactericidal activity, in particular, antituberculosis activity.
EFFECT: valuable medicinal properties of modified chitosan.
1 tbl, 1 dwg, 3 ex
FIELD: natural compounds technology.
SUBSTANCE: chitosan preparation process comprises breaking naturally occurring chitin-containing material, charging it into reactor, demineralization with 6-7% aqueous hydrochloric acid, deproteination with sodium hydroxide solution at 85-95°C, deacetylation with sodium hydroxide solution on heating, decoloration, and washing with water after each stage to pH 6.5. Process is characterized by that chitin-containing material broken to achieve fraction 0.5-6 mm is fed simultaneously into a number of reactors, wherein demineralization is effected with aqueous hydrochloric acid stream at 85-95°C for 1.5 h while controlling pH in each reactor exit to achieve acid concentration in each reactor exit the same as concentration of the initial acid by way of feeding it in a continuous manner. In addition, deproteination is carried out with 6-7% sodium hydroxide solution stream for 1.5 h followed by discharging treated material into autoclave to perform deacetylation simultaneously with decoloration using 50% sodium hydroxide solution at 130-140°C in inert gas environment and in presence of 3-5% hydrogen peroxide solution used in amount 3-5% of the total volume of mixture.
EFFECT: enhanced process efficiency.
FIELD: chemical technology.
SUBSTANCE: invention relates to methods for preparing water-soluble saline complexes (associates) of hyaluronic acid with d-metals of IV, V and VI periods of Mendeleyev's periodic system of elements that can be used in pharmacology and cosmetology. Invention describes a method for preparing water-soluble saline complexes of hyaluronic acid involving preparing an aqueous solution of salt of d-metal of IV, V and VI periods of periodic system and its mixing with hyaluronic acid sodium salt, holding the mixture, its stirring, dilution with water and isolation of the end product. For mixing method involves using the amount of aqueous salt of abovementioned d-metal that is equivalent to the amount of carboxy-groups of hyaluronic acid sodium salt or in the limit from 0.95 to 1.10. After dilution with water the solution mixture is subjected for ultrafiltration on separating membranes with simultaneous washing out with aqueous salt solution of abovementioned d-metal firstly and then with deionized water followed by concentrating the product. By another variant for mixing the method involves the amount of aqueous solution of d-metal salt lesser of the equivalent amount of carboxy-groups in hyaluronic acid sodium salt. After dilution with water the mixture is subjected for ultrafiltration on separating membranes with simultaneous washing out with deionized water followed by concentrating the product also. Method is characterized by the decreased time of processes and simplicity.
EFFECT: improved preparing method.
2 cl, 1 tbl
FIELD: medicine, food processing industry, in particular production of depolymerized chitosane and products based on the same.
SUBSTANCE: claimed method is based on using of chitosanase in acetic acid medium and spray drying of and depolymerized chitosane and is characterized in that obtained depolymerized chitosane is preliminary converted in non-ionized form by neutralizing of bound acetic acid with ammonium hydroxide followed by precipitation in ethanol and air drying. Further interaction is carried out with ammonium lipoate or glutathione in aqueous medium. Claimed products may be used individually or in combination with other components.
EFFECT: new products for food processing industry and medicine.
4 cl, 2 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for preparing modified glycosaminoglycans possessing analgesic properties. Method involves interaction of glycosaminoglycans with 1-phenyl-2,3-dimethyl-4-aminopyrazolone-5-(4-aminoantipyrine) in aqueous medium at pH = 4.7-4.8 in the presence water-soluble 1-ethyl-3-[3-(dimethlamino)propyl]carbodiimide as a condensing agent at room temperature followed by purification from low-molecular reagents. Method involves a single step that simplifies technology in preparing modified glycosaminoglycans.
EFFECT: improved preparing method.
FIELD: natural substances, chemical technology.
SUBSTANCE: invention relates to a method for preparing chitosan and purification from components of the reaction mixture - low-molecular products of deacetylation and alkali excess. Invention relates to a method for purifying chitosan prepared by solid-state method involving treatment of reaction mass with extractant consisting of 3.3-20.0% of water, 32.2-57.1% of ethyl acetate and 24.6-64.5% of ethanol at the extractant boiling point. Also, invention relates to a method for purifying chitosan prepared by suspension method and involving treatment of the reaction mass with ethyl acetate and the following treatment with extractant consisting of 6.2-25.0% of water, 12.5-62.5% of ethyl acetate and 31.3-62.5% of ethanol at the extractant boiling point.
EFFECT: improved isolating and preparing method.
3 cl, 2 tbl, 1 dwg